.TH biopattern 8  "2022-02-21" "USER COMMANDS"
.SH NAME
biopattern \- Identify random/sequential disk access patterns.
.SH SYNOPSIS
.B biopattern [\-h] [\-d DISK] [interval] [count]
.SH DESCRIPTION
This traces block device I/O (disk I/O), and prints ratio of random/sequential I/O
for each disk or the specified disk either on Ctrl-C, or after a given interval in seconds.

This works by tracing kernel tracepoint block:block_rq_complete.

Since this uses BPF, only the root user can use this tool.
.SH REQUIREMENTS
CONFIG_BPF and bcc.
.SH OPTIONS
.TP
\-h
Show help message and exit.
.TP
\-d
Trace this disk only.
.TP
interval
Print output every interval seconds, if any.
.TP
count
Number of interval summaries.
.SH EXAMPLES
.TP
Trace access patterns of all disks, and print a summary on Ctrl-C:
#
.B biopattern
.TP
Trace disk sdb only:
#
.B biopattern -d sdb
.TP
Print 1 second summaries, 10 times:
#
.B biopattern 1 10
.SH FIELDS
.TP
TIME
Time of the output, in HH:MM:SS format.
.TP
DISK
Disk device name.
.TP
%RND
Ratio of random I/O.
.TP
%SEQ
Ratio of sequential I/O.
.TP
COUNT
Number of I/O during the interval.
.TP
KBYTES
Total Kbytes for these I/O, during the interval.
.SH OVERHEAD
Since block device I/O usually has a relatively low frequency (< 10,000/s),
the overhead for this tool is expected to be low or negligible. For high IOPS
storage systems, test and quantify before use.
.SH SOURCE
This is from bcc.
.IP
https://github.com/iovisor/bcc
.PP
Also look in the bcc distribution for a companion _examples.txt file containing
example usage, output, and commentary for this tool.
.SH OS
Linux
.SH STABILITY
Unstable - in development.
.SH AUTHOR
Rocky Xing
.SH SEE ALSO
biosnoop(8), biolatency(8), iostat(1)
